Ignition controlling device for internal combustion engines



M. H. ELKIN IGNITION CONTROLLING DEVICE FOR INTERNAL COMBUSTION ENGINESSept. 7, 1943.

Filed Aug. 22, 1940 2 Sheets-Sheet l INVENTOR. 472mm fike'n/ ATTORNEY.

wwwS/S Sept. 7, 1943. M. H. ELKIN ,3

IGNITION CONTROLLINQDEVICE'FOR INTERNAL COMBUSTION ENGINES Filed Aug.22, 1940 2 Sheets-Sheet 2 JTLanwe/.

ATTORNET'.

Patented Sept. 7, 1943 IGNITION CONTROLLING DEVICE FOR IN TERNALCOMBUSTION ENGINES Manuel IL, Elkin, Elmira Heights, N. Y., assignor toBendix Aviation Corporation, South Bend, Ind., a corporation of DelawareApplication August 22, 1940, Serial No. 353,663

9 Claims.

The present invention relates to an ignition controlling device forinternal combustion engines and more particularly to a device formomentarily grounding the ignition circuit of an internal combustionengine while a variable speed transmission operated thereby is being Itis another object to provide such a device which is reliable andvuniform in operation while being simple and economical in construction.

Further objects and advantages will be apparent from the followingdescription taken in connection with the accompanying drawings in which:

Fig. 1 is a semi-diagrammatic representation of an internal combustionengine and transmission with a preferred embodiment of the inventionapplied thereto for controlling the ignition system of the engine;

Fig. 2 is a top view partly in section of a preferred form ofthermostatic controlling vice;

Fig. 3 is a side elevation of the same partly in vertical section;

Fig. 4 is an end view of the thermostatic control device from the lefton line 4-4 in Fig. 3, the casing being sectioned; and

Fig. 5 is an end view from the right in Fig. 3.

In Fig. 1 of the drawings there is illustrated in dotted lines theoutline of an internal combustion engine I with clutch housing 2 andvariable speed transmission 3 operated thereby, all be-' ing understoodto be of conventional construction. An automatic controlling device 4for the transmission 3 is mounted thereon in any suitable manner andcomprises a shift rail 5 adapted to engage a shift arm 6 of thetransmission to effect the changes in speed ratio. The variable speedtransmission and its control form no part of the present invention andfurther description thereof is accordingly deemed unnecessary.

The engine I is provided with an ignition systern of conventional typecomprising a battery 3 grounded at B and connected through an ignitionswitch 3 to the primary of an induction coil H, the secondary of whichis connected to the spark plugs of the engine in the usual manher. Theignition circuit from the primary of theinduction coil H is completedthrough a lead l2 to a timer l3 grounded at N.

According to the present invention, means are provided for grounding thelead I! of the ignition circuit during the shifting operation of thetransmission in order to facilitate the operation by momentarilyrelieving the transmission of the driving force of the engine. As hereillustrated, a grounding circuit is provided comprising a lead l5connected to ignition lead H, a fixed contact It, a contact I! mountedon a spring arm it! so as to normally engage the contact it, a lead I 9and a grounding switch indicated generally by numeral 2|. Switch 2icomprises a fixed contact 22, a ground contact 23 and a bridging contact26. Contact 25 is normally disengaged from the fixed contacts and ismounted on a slidable plunger 25, the lower end of which normally restsin a notch 28 in the shift rail 5. The parts are so proportioned thatinitial sliding movement of the shift rail 5 to perform its shiftingfunction, raises the plunger 25 and bridging contact to close the switch2! and hold it closed until the movement of the shift rail is completed.At that time, a second notch 21 in the shift rail comes into registrywith the lower end of the plunger 25, thereby permitting the switch litto open.

Means are provided for opening the normally closed contacts I6, I! aftera short predetermined time interval so as to break the ignitiongrounding circuit and rehabilitate the engine ignition circuitirrespective of the completion of the shifting movement of thetransmission. As here shown, this is accomplished by means of a springarm 28 adapted to engage a block of insulation 29 on the contact arm I8and flex the arm It) to move contact I'l out of engagement with contactIt. This action of the arm 28 is, however, normally restrained by a wire3| attached at 32' to the free end of arm 28 and securely anchored at 33at a point above and adjacent to the anchorage of the arm 28. Wire 3| ismade of suitable thermally expansive material such as tungsten, andmeans are provided for heating the wire to cause it to expand and permitthe spring arm 28 to open contacts it, H. As here shown, this means isin the form of a heating circuit comprising a lead 3% connected to'theignition switch 9, and to the wire {it through a resistors-ti. Resistor35 is of such.

value as to secure the desired rate of heating of wire 3| in order tocontrol the time interval for the opening of the contacts l6, I1. Theheating circuit for wire 3| is completed through the spring arm 28 and alead 33 to a fixed contact 31 in grounding switch 2|, whereby closure ofthe switch 2| causes the bridging contact 24 thereof to connect thecontact 31 to the ground contact 23.

The thermostatic controlling device including the contacts l6, I1, ispreferably formed as illustrated in Figs. 2 to 5 inclusive. As thereillustrated, a mounting plate 33 of insulating material serves tosupport a bracket 39, the inner end of which carries the fixed contactl6 and the outer end of which supports the spring arm l8 carryingmovable contact I1. Bracket 39 also supports the spring arm 23 foropening the contacts and has a laterally extending arm 4| having aflared opening 42 adapted to receive the anchorage 33 of the wire 3|.The anchorage 33 preferably takes the form of a bead of fuseableinsulating material such as borax glass which is fused on the wirewithin the opening 42 while the wire is maintained under tension. Aterminal 43 is provided for attachment of lead 34, a terminal 44 forattachment of lead |9, a terminal 45 for attachment of lead l5, and aterminal 46 for attachment of lead 36. The entire unit is preferablyencased in a metal cup 41 fixed to the plate 38 in any suitable way asby means of a clamping ring 48.

In operation, closure of the ignition switch 3 renders the ignitioncircuit of the engine operative in the usual manner, the groundingcircuit for the ignition being open at switch 2|, and the heatingcircuit for the wire 3| being also open at said switch. Upon initiationof the shifting movement of rail 5, switch 2| is closed, therebygrounding the ignition circuit of the engine through lead l5, contactsl6, l1, lead I9, switch contacts 22, 24 and 23 to the ground. At thesame time, the heating circuit for the wire 3| is completed through lead34, resistor 35, lead 36, switch contacts 31 and 24 to the groundcontact 23 so that the wire 3| begins to heat up. If the shiftingoperation takes place in the normal manner, it is completed in a fewtenths of a second, and the plunger 25 of switch 2| falls into the notch21 of the shift rail 5, thus opening switch 2|. If, for any reason, theshifting operation is not completed, however, and the rail 5 stops at anintermediate point, the wire 3| becomes heated sufficiently to expandand permit the spring arm 28 to push contact I! out of engagement withcontact I8, thus opening the grounding circuit for the engine ignitionand restoring the operation of the engine. The heating circuit for wire3| remains closed as long as switch 2| is held closed, so that there isno possibility of undesired grounding of the engine ignition.

It will be readily appreciated that since the mass of the wire 3| isvery small, the heating up and cooling off of the wire may take placequite rapidly, so that any suitable short time interval for the openingof contacts i6, i1 may readily be secured, and this time interval willbe substantially constant even though the device is repeatedly operated.

Although but one form of the invention has been shown and described indetail, it will be understood that other forms are possible and variouschanges may be made in the design and arrangement of the parts withoutdeparting from the spirit of the invention as defined in the claimsappended hereto.

What is claimed is:

1. In combination with an ignition system of an internal combustionengine, a normally open grounding circuit therefor including a pair ofnormally closed contacts, spring means for opening the contacts, atension wire oi. thermally expansive material restraining the springmeans from opening the contacts, means for closing the groundingcircuit, and means for heating the wire to cause it to release thespring means.

2. In combination with an ignition system of an internal combustionengine, a normally open grounding circuit therefor including a pair ofnormally closed contacts, spring means for opening the contacts, atension wire of thermally expansive material restraining the springmeans from opening the contacts, means for closing the groundingcircuit, and means rendered operative by completion of the groundingcircuit for heating the wire to cause it to release the spring meansafter a predetermined time interval.

3. In combination, an internal combustion engine having an electricalignition system, a variable speed transmission driven thereby, agrounding circuit for the ignition system including a pair of normallyclosed contacts and a normally open switch, means for closing the switchduring shifting of the variable speed transmission, spring means foropening the contacts, restraining means for the spring means including atension wire of thermally expansive material, and means for heating thewire to cause it to release the spring means.

4. In combination, an internal combustion engine having an electricalignition system, a variable speed transmission driven thereby, agrounding circuit for the ignition system including a pair of normallyclosed contacts and a normally open switch, means for closing the switchduring shifting of the variable speed transmission, spring means foropening the contacts, restraining means for the spring means including atension wire of thermally expansive material, and means renderedoperative by closure of said switch for heating the wire to cause ity torelease the spring means after a predetermined time interval.

5. In combination with an internal combustion engine and an automaticvariable speed transmission operated thereby, an ignition system for theengine, a grounding circuit for the ignition system including a normallyopen switch and a set of normally closed contacts, means responsive tothe initiation of the shifting movement of the transmission for closingsaid switch to complete the grounding circuit, spring means for openingthe contacts, a thermally expansive wire restraining said opening means,and means responsive to shifting of the transmission for heating thewire to cause it to release the opening means.

6. In combination with an internal combustion engine and an automaticvariable speed transmission operated thereby, an ignition system for theengine, a grounding circuit for the ignition system including a normallyopen switch and a set of normally closed contacts, means responsive tothe initiation of the shifting movement of the transmission for closingsaid switch to complete the grounding circuit, spring means for openingthe contacts, a thermally expansive wire restraining said opening means,and a heating circuit for said wire including said normally open switch.

7. In an ignition controlling device for internal combustion engines,means for rendering the ignition system of the internal combustionengine inoperative, means for restoring the operability of the ignitionsystem after a predeter mined time including an elastic member and athermally expansive wire normally restraining the elastic member, andmeans for heating the wire responsiveto actuation of the first-namedmeans.

8, In combination with an internal combustion engine and. a variableoperated thereby, means for rendering the ignition system inoperativeduring shifting of the transmission, means for restoring the operabilityof the ignition system after a predetermined speed transmission 15 wirerendered operative by actuation oi! said time irrespective of theposition 01' the transmission including an elastic member and athermally expansive wire normally restraining the elastic member, andmeans for heating the wire when the transmission is intermediate any ofits operative positions..

9. In an ignition controlling device for internal combustion engines,means for rendering :the ignition momentarily inoperative including aswitch, and means for restoring the operability of the ignition systemafter a predetermined time interval including an elastic member and athermally expansive wire normally restraining the elastic member, andmeans for heating said switch. I

MANUEL H. ELKIN.

